A thermosyphon heat exchanger can be a powerful cooling device for cooling power electronic modules. It can increase cooling performance while decreasing weight, volume and required air pressure drop. A thermosyphon heat exchanger uses the phase transition of a refrigerant to subduct the heat of the electronic module (e.g., to vaporize the refrigerant by the heat of the power electronic module). The refrigerant-vapor rises in a closed loop of tubes and can be conducted to an actively cooled condenser, where the vapor condenses back to the liquid refrigerant. The re-condensed refrigerant can be lead back to vaporizing part of the cooling circuit.
U.S. Pat. No. 6,357,517, the disclosure of which is hereby incorporated by reference in its entirety, discloses thermosyphon heat exchangers for power electronic modules. Electronic modules can be mounted on vertically arranged vapor passages and the refrigerant condenses in separated condensed liquid passages. Thus, the rising vapor may not interfere the sinking and condensing refrigerant. Known thermosyphon heat exchangers is that they are custom made for very small quantities. Thus, an individual adaption of the size of vapor passages and condensed liquid passages for the conditions of different power electronic modules would further reduce the quantities of the thermosyphon heat exchangers. Large or many vapor passages or condensed liquid passages, respectively, enlarge the cooling power of the thermosyphon heat exchanger, but also increase production costs and volume.